Determining path status for your HA pair
If you want to remove a module from your HA pair , you need to know if the path you plan to disrupt is redundant. You can use the storage show disk -p command to indicate whether the disks have redundant paths.
If the disks have redundant paths, you can remove the module without interfering with the storage system’s ability to serve data. However, if that module provides the only path to any of the disks in your HA pair , you must take action to ensure that you do not incur system downtime.
Enter the storage show disk -p command on your system console.
This command displays the following information for every disk in the
- Primary port
- Secondary port
- Disk shelf
Examples for configurations with and without redundant pathsThe following example shows what the storage show disk -p command output might look like for a redundant-path HA pair consisting of Data ONTAP systems:
PRIMARY PORT SECONDARY PORT SHELF BAY ------- ---- --------- ---- ----- --- 0c.112 A 0b.112 B 7 0 0b.113 B 0c.113 A 7 1 0b.114 B 0c.114 A 7 2 0c.115 A 0b.115 B 7 3 0c.116 A 0b.116 B 7 4 0c.117 A 0b.117 B 7 5 0b.118 B 0c.118 A 7 6 0b.119 B 0c.119 A 7 7 0b.120 B 0c.120 A 7 8 0c.121 A 0b.121 B 7 9 0c.122 A 0b.122 B 7 10 0b.123 B 0c.123 A 7 11 0c.124 A 0b.124 B 7 12 0b.125 B 0c.125 A 7 13
Notice that every disk (for example, 0c.112/0b.112) has two active ports: one for A and one for B. The presence of the redundant path means that you do not need to fail over a node before removing modules from the system.
The following example shows what the storage show disk -p command output might look like for an HA pair consisting of Data ONTAP systems that do not use redundant paths:
filer1> storage show disk -p PRIMARY PORT SECONDARY PORT SHELF BAY ------- ---- --------- ---- ----- --- 5b.16 B 1 0 5b.17 B 1 1 5b.18 B 1 2 5b.19 B 1 3 5b.20 B 1 4 5b.21 B 1 5 5b.22 B 1 6 5b.23 B 1 7 5b.24 B 1 8 5b.25 B 1 9 5b.26 B 1 10 5b.27 B 1 11 5b.28 B 1 12 5b.29 B 1 13
For this HA pair , there is only one path to each disk. This means that you cannot remove a module from the configuration and disable that path without first performing a takeover.